4th International Symposium “Molecular Order and Mobility in Polymer Systems”. St.Petersburg, June 3-7, 2002.
MONOLAYER BEHAVIOUR OF POLYAMIC ACID TERT-AMINE SALT AT THE AIR-WATER INTERFACE AND THE ELECTRET PROPERTIES OF Si-SiO2 STRUCTURE WITH POLYIMIDE LANGMUIR-BLODGETT FILMS
S.I. Goloudina*, D.A. Kozodaev*, V.M. Pasyuta*, V.V. Luchinin*, V.I. Zakrzhevsky*, V.P. Sklizkova**, I.V. Gofman**, V.V. Kudryavtsev**
*St. Petersberg State Electrotechnical University, Prof. Popov str., 5, St.Petersburg, 197376, Russia
**Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoy pr., 31, St.Petersberg, 199004, Russia
In this study we investigated the p -A isotherms and the stability curves of the monolayers of polyamic acid tert-amine salt (PAAS). To prepare PAAS the rigid-chain polyamic acid and tert-amine as O, O’, O’’ – trihexadecanoytriethanolamine were used. Polyamic acid was produced on the base of dianhydride of 3, 3’, 4, 4’ – bipheniltetracarboxylic acid and o-tolidine. It was shown that PAAS forms well ordered and stable monolayers at the air-water interface. Monolayers were transferred by Y-type deposition onto the silicon dioxide substrate. The Langmuir-Blodgett films of PAAS, having 3, 5 and 9 layers, were converted into polyimide by thermal treatment.
The electret properties of the SiO2-polyimide films including charge stability, transport of detrapped charges in the bulk, were studied. The investigated samples were charged by a corona method. The SiO2 electret film based on silicon possesses good storage ability of negative and positive charges after polyimide surface modification.
The trapping and drift of injected charges from the upper surface to the bulk oxide. is suggested to be the dominant mechanism of charge storage in the SiO2 electret. The experimental results show that the polyimide Langmuir-Blodgett films on silicon dioxide forms the additional deep levels of electrically active defects. The influence of charge trapping on the SiO2-polyimide interface has been discussed.
S.I. Goloudina, D.A. Kozodaev, V.M. Pasyuta, V.V. Luchinin, V.I. Zakrzhevsky, V.P. Sklizkova, I.V. Gofman, V.V. Kudryavtsev. Monolayer behaviour of polyamic acid tert-amine salt at the air-water interface and the electret properties of Si- SiO2 structure with polyimide Langmuir-Blodgett films // 4th International Symposium “Molecular Order and Mobility in Polymer Systems”. St.Petersburg, June 3-7, 2002, p. 139